differences between Manent and Areca

[Tommy]

I found this software via the Slashdot discussion <http://
tech.slashdot.org/article.pl?sid=08/08/18/0033208> and wanted to know
the differences between it and Areca <http://areca.sourceforge.net/>
which was also mentioned in the thread.

They seem to accomplish the same goals.

Thanks for giving software to the world!

-Tommy

[sakeman]

On Jan 6, 2:53 pm, Tommy <tkesw...@gmail.com> wrote:
> I found this software via the Slashdot discussion <http://
> tech.slashdot.org/article.pl?sid=08/08/18/0033208> and wanted to know
> the differences between it and Areca <http://areca.sourceforge.net/>
> which was also mentioned in the thread.

The biggest difference at least is the language used for developing
these software. Manent is written with (in my opinion) light Python
and Areca is written with (in my opinion) heavy Java. For my servers
the quick, light, and compact Python interpreter is much more
attractive option instead of memory and resource consuming Java. On
the other hand all my servers already have Python and I would not like
to install Java just to use a backup software.

[Sasha]

I have nothing bad to say about Areca, and I wish Manent was already
at the same degree of maturity.
I'm working on it though, and of course, collaboration is welcome.

I wouldn't say that Python is that much more lightweight than Java, in
any case what Manent is doing is:
- scanning the file system. Here the bottleneck is the disk subsystem.
- accessing the local database. Here, again, the database engine is
written in C, so it doesn't matter which glue language is calling it.
- uploading stuff to the network. Python is definitely not the
bottleneck.
- computing hashes, compressing, encrypting. All done in C.
So, it wouldn't make a lot of difference if it was written in Java.
In hindsight, it might be better to bite the bullet and have written
it in C++, but then it would take much more time to develop and most
likely not be anywhere usable today. The reason for C++ is, however,
not efficiency (not that I'd oppose it), but the opportunity to
resolve all kinds of library incompatibilities with which I'm stuck in
python.

Now for the real differences with Areca (note that I'm judging from
its description only, I haven't seen the code):
- Manent is optimized to be as frugal as possible with storage
resources, i.e., space and bandwidth. It can live with a storage that
likes big files (potentially DVDs), relatively small files (like
email). It can make progress over a crappy network connection, i.e.,
if your backup diff is 100G but your network connection drops after
every 20M, it will eventually succeed.
- Manent notices that the data is shared in your own system. While
pure sharing is hypothetical, moving files around is something that
should not cost you traffic and storage space.
- Manent explicitly supports storing several backups storing data at a
shared place, and will even share the data between them provided that
they share an encryption key.
- There are no different modes like full/incremental, encrypted/not
encrypted, full/delta and so on. Everything is turned on, and so all
the capabilities are always present...